(a) Field of the Invention
The present invention relates to an image display device using a diffractive element.
(b) Description of the Related Art
In recent years, 3D stereoscopic image display devices have attracted interest, and various 3D image display methods have been researched.
One of the most generally used methods for displaying stereoscopic images is binocular disparity. In binocular disparity, an image which reaches a left eye and an image which reaches a right eye are displayed in the same display device. The two images are reach the left eye and the right eye of an observant the same time from different angles, and as a result the observer perceives a 3D effect.
In this case, producing separate images for the left eye and the right eye is accomplished using either a barrier over pixels and a lenticular lens, which is a kind of cylindrical lens over pixels.
A stereoscopic image display device that uses the barrier forms a slit on the barrier and divides the image from the display device into a left-eye image and a right-eye image through the slit to be inputted into the left eye and the right eye of the observer, respectively.
A stereoscopic image display device that uses the lens displays the left-eye image and the right-eye image and divides the image from the stereoscopic image display device into the left-eye image and the right-eye image by changing a light path through the lens.
It is desirable to have a display device that can change the viewing mode from 2D image display methods to stereoscopic image display methods. Such 2D-to-3D image displays are being developed, and to this end, switchable lenses are being developed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.